The prior art, the pedal propulsion system described in Ketterman, U.S. Pat. No. 6,022,249, the disclosure of which is expressly incorporated herein by reference, allows the user to adjust the pedals forward and backward to accommodate different human leg lengths. The pedal support and cable guide of the drive has multiple predefined adjustment holes. The slidable pin locks into these holes and translates the user's pedal force by means of the pedal shafts into the drive system.